Since 1996, when the first genetically modified crops were commercialized, the use of genetically modified crops has increased by 10% or more each year and this estimation is likely to increase in the coming years. These crops are being utilized for both animal and human consumption, which has been increasing with the massive increase in world population. Genetically modified crops are created in the process of genetic engineering by inserting a foreign gene into the genome of the organism in order to increase resistance against pests and pesticides that have been causing crop loss for centuries. This scientific approach is now in use by approximately 8.5 million farmers around the world; 90% of them living in developing countries. The use of genetically modified crops has not only benefitted the international market but has also allowed scientists to recreate species that have had previously been extinct.
Unlike natural selection or selective breeding, genetic engineering has allowed more predictable and improved results. 7, 8 & 12 Figure 1: The above demonstrate a DNA molecule that is composed of four different types of nucleotide bases that are paired together forming the following pairs: adenine-thymine and cytosine-guanine. The basis could be either paired as A: T or T: A and C: G or G: C; abbreviations for the four bases. 14, 16 & 17 Genetic engineering is the formation of a whole new range of genes, proteins and new organisms, through the use of one out of the three different methods. An existing gene can be either altered or turned off or instead, could be replaced by a foreign gene in the process of genetic engineering. This exchange of genes among different organisms is only possible due to the universal genetic code which is a specific sequence of nucleotides in DNA or RNA that determine the characteristics and the functioning of an organism. A gene, which is the physical unit of heredity, contains a molecule that decides the function and structure of all organisms, called the DNA.
The DNA molecule is made up of four different nucleotide bases that are linked up together in pairs within a long string, forming a code. Whether it is a blade of grass or a human being or a pond scum or an insect, their DNA consists of the same nitrogenous bases (figure 1) but arranged in a different sequence. Changing the order of the nucleotides would create different organisms from different species with different characteristics. Having a universal code for all organisms allows scientists to be able to exchange different genes among organisms of different species in order to create a new organism or range of genes & proteins, without any complications. 4, 14 & 20 As previously mentioned, genetic engineering involves three different methods where either an existing gene can be altered in order to improve its performance so as to express it at a higher level; e.g. growth hormones or an existing gene could be deactivated to prevent a particular expression of the trait, or where another foreign gene could be inserted into the genome to enable the organism to express the desired trait.
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These three methods could be used for different purposes and in different circumstances. Gene therapy is a technique involving altering or deactivating an existing gene in order to correct a faulty gene that leads to disease development in an organism. The gene could be repaired by various methods which either involve changing the limit to which a gene could be turned off or on, or swapping an abnormal gene for a normal one, or repairing an abnormal gene via selective reverse mutation. Gene therapy allows encoded proteins to perform normally and carry out functions that once seemed impossible for the organism. 1 & 3 Figure 2: The above is a demonstration of how a restriction enzyme cuts up a DNA molecule, leaving behind equally parted recognition sites. Sometimes the recognition sites could be overhanging “sticky end” or non-overhanging “blunt end”, depending on the restriction enzyme. 1, 18 & 19
Unlike gene therapy, gene cloning focuses on making large quantities of a piece of the desired DNA that has been isolated from cells that grow in science laboratories. Genetically modified crops are created via gene cloning which involves adding a foreign gene into the host DNA and then duplicating the resultant gene. This technology is not yet adopted by all countries around the world, mainly because of its expense and high scientific requirements. In order to clone a gene, DNA is first extracted from the desired gene and then is cut up in a controlled manner using a restriction enzyme. Restriction enzymes are molecular scalpels that are capable of cutting up a double-stranded DNA molecule into very exact sequences of 4 to 8 base pairs known as the recognition sites, which may either result in sticky ends or blunt ends (figure 2). Both, the DNA and the plasmid (it is a vector; DNA molecule that transports foreign genetic material into another) are cut up using the same restriction enzyme so as to produce similar sticky ends.
Using DNA ligase in the process of ligation, the sticky ends of the two are recombined by base-pairing known as annealing to produce a recombinant plasmid. Once joined together, the recombinant plasmid is then introduced into a bacterial cell by inserting it into a bacterial culture. This plasmid will then be accepted by the bacteria in the process of transformation, under appropriate conditions. The actual cloning process takes place only if the bacteria cell containing the recombinant plasmid is ready to reproduce. Once ready, then the recombinant plasmid replicates independently inside the bacterium to produce many copies of the target gene. 1 As stated earlier, genetically modified crops are created using the above method. Unlike selective breeding or natural selection, the results for genetic engineering are more predictable as to when creating genetically modified crops, DNAs of two different species with impressive traits are combined together to produce high quality and fully resistant to pests and pesticides, crops.
However, in this case, the recombinant plasmid is straight away introduced into the plant cells where it combines with the plant’s chromosomal DNA. Later, before being planted out to grow normally, these transformed plant cells are grown by tissue culture. Fine examples of GMOs would be Bt-corm, Bt-potatoes, Bt-sweet corn etc. The main purpose behind creating such crops is either improving crop quality or providing tolerance and protection against pests, pesticides and harsh climatic conditions. To this point, this approach has turned out to be beneficial to most food industries and this success is continued to be expected in the coming days. 1 Figure 3: The above figure indicates the increase in the use of genetically modified crops by both developing and developed countries and the world on the whole. As we can see, the use of genetic engineering has increased rapidly in developed countries mainly due to the reason that these countries are capable of affording such expensive technology.
The increase in the use of this technology does not seem very high in developing countries as these countries are not entirely capable of affording such expensive scientific equipment. Genetic engineering is a worldwide discussed issue that has generated a lot of controversies and public interest since it was first commercialized. The use of genetically modified crops has been increasing since 1996 and is expected to increase in the coming years. Figure 3 & 5, explains the wide range of use of genetically modified crops by 21 countries. It suggests that 95% of the total area of five countries; the USA, Argentina, Brazil, Canada and China, is utilized for cultivating genetically modified crops. This high percentage has aroused concerns among quite a few scientists as they are unsure about the benefits of genetically modified crops. Jane Rissler a senior staff scientist with the Union of Concerned Scientists has lately been worried about the safety of using GM crops. She says “Our point of view is that we’re skeptical of many of the benefits.
We’re worried about the uncertainties and the risks.” However, she also admits that the positive factors of genetically modified crops are as important, “No. We’re not opposed to genetically engineered crops across the board. We do see this as a powerful new technology.” From her perspective, the negative factors of GM crop usage are significant but there are also important positive factors. Their knowledge of the negative effects suggests this technology be used in limited ways. 7 & 9 Figure 4: The above figure explains how Bt-corn helps provide protection to the plant by killing pests that feed on the crop. The intestine of the pest ruptures when the toxin known as Bt is ingested. Consumption of these crops only leads to the death of pests; it is ineffective towards humans and other animals. 15
Genetic engineering has been criticized since it came into action. Excuses used against this technology engage topics such as humans should not be transforming other organisms or biotechnologists are playing god. However, no one has acknowledged how successful genetic engineering has been in addressing specific local and global issues. Genetic engineering aims to create crops that are better resistant to pests, pesticides, diseases and extreme climatic conditions. These types of crops are capable of growing among poisonous pests and in harsh circumstances. For example, Bt-enhanced plants contain genes that are deadly to pests. Instead of wasteful and expensive spraying of toxic pesticides that harm crops, the pests will contain the genes of Bacillus thuringiensis (Bt). After tasting the crop, the pest will then go off and in a period of fewer than 30 hours, it will die. Figure 4 explains how Bt-corn, a Bt-enhanced plant, could lead to the killing of pests. The use of Bt-enhanced crops has saved 10 times more than the crops saved earlier.
The use of better resistant crops has to lead to an increase in the amount of produce. The decrease in crop loss has caused productivity to increase which in turn has to lead to financial growth and economic growth. Their use of such a technique is not only beneficial for the food industries but also for the population and with the increase in productivity, it is now easier to keep up with the hunger of the massive population growth. 6, 5 & 15 As stated earlier, genetic engineering is a controversial subject with its own benefits and limitations. One of the benefits of genetic engineering would be to reduce the costs of production. The increase in productivity has lead to a decrease in the price of goods. The industries prefer selling out as much food as possible at lower rates, due to high productivity. This means that the poor will be able to afford more food than normal and be self-sufficient. This is one of the main benefits as it will not only affect the society financially but also socially as then the poor will be able to live more comfortably and keep up with the society. Another benefit of genetic engineering would be crop diversity.
As mentioned earlier, genetic engineering could produce organisms from various species due to the universal genetic code. With the use of genetic engineering, scientists could create crops with certain highly desirable traits and more susceptible to natural disasters such as disease outbreaks. Also, they could invent species that could be used for medical purposes and help cure terminal diseases. With the use of genetic engineering, they will capable of producing vaccines, pharmaceuticals and other materials required in the medical industry. Genetic engineering is not only benefitting the medical and food industries but also is providing increased profits to the farmers. This technology has helped to create crops that are considered effective means of dealing with pests and this is beneficial for the farmers as growing crops is the only means of income for them. 6 & 5 Figure 5: The above demonstrates a wide range of use of genetically modified crops. The figure suggests that the better the economic conditions of a country, the larger the area consumed by genetically modified crops. It gives us an overall idea of how much area on this planet is covered by GM crops.
With benefits, genetic engineering also has quite a few limitations, the main one being the resistance of bugs against genetically modified crops. It is not necessary that all bugs are affected by these as Gm crops do not guarantee 100% resistant against all types of pests and also due to some genetic mutation some pests manage to survive. It might be that some pests remain uninfected by the use of Bt-enhanced plants. These uninfected bugs will not then only survive but also create a reproductive edge, producing Bt-resistant bugs that will then control the area. Over a period of time, these bugs will only breed Bt-resistant bugs which may lead to crop loss again; their offsprings can be susceptible to Bt-toxin. Another limitation of genetic engineering would be that it is costly and requires high technological equipment. Not all countries are capable of affording such expensive equipment and technology, so not all farmers all over the world will have access to this scientific approach. Figure 5 explains how many countries have access to GM technology. Sometimes during genetic engineering, some of the processes could go wrong.
The consequences would be irreversible and severe if anything goes wrong. This is a very common mistake made during this process. And quite often it could result in causing major damage. The results of this technology are unpredictable and not necessarily safe always. 2 & 9 Discussing the effects of genetic engineering from Jane Rissler’s perspective also brings up quite a few interesting arguments. Genetic engineering is done haphazardly. The technique involves inserting genes anywhere inside the plant cell; its location is never recognized which may interrupt other gene functions and cause disorders. It is not an exact process and no one can predict what will happen. The technology is new and it hasn’t been monitored a lot in the environment which brings a lot of uncertainties with it. One cannot assure if it is safe. Currently, there haven’t been any incidences of allergies from GM crops reported but who knows if the effects are long-term impacts. The disease could take longer to develop in the human body.
Some scientists argue about Bt-enhanced crops could contain chemical substances that could lead to allergies. This technology has been combining various proteins from organisms that do not belong to our usual diet; this might lead to some new allergens that are unknown. One of the main arguments Jane Rissler puts forward is, why not label genetically modified food in the market? She says “Well, there is no evidence of harm. How would we know if someone had gotten ill from genetically engineered food if it’s not labelled?” She has been insisting on having genetically modified crops sold with labels even if they are not harmful. She mentions “the absence of evidence is not the absence of harm. Look at the fact that we’re not able to track whether there’ve been any problems and the fact that there are very few papers in the published literature on the safety of genetically engineered food for human consumption.” She wants evidence as there is very little information about the long-term impacts of genetically engineered food and this move does not seem very elegant to her. She only insists on having evidence. 2, 9 & 13
Gene flow in the environment is another issue that Jane Rissler seems very concerned about. Humans have been polluting the ecosystem with species that were introduced as biological control agents at first but eventually became a threat to the environment, for example, Japanese Ladybug. Genetic engineering could lead to gene pollution, putting the ecosystem at threat. Also, genetic engineering has become a threat to monarchs and butterflies. Bug-resistant crops could lead to the extinction of butterflies. After Bees, butterflies play an essential role in the process of pollination and flower cultivation and are good indicators of environmental health. Their extinction could affect the flowering process and flower species. Genetic engineering is a fairly new concept and playing around with it may create problems related to genetic mutation which will not only affect the environment but also all living organisms. And as mentioned earlier, this process is irreversible and its consequences will not necessarily be safe. Genetic mutation could cause diseases that might be incurable and lead to epidemic diseases. Genetic engineering might result in causing unknown risks to the environment or human health. It is a new technology without any proof of it being safe. 9 & 8
In Jane Rissler’s views, technology is not a solution to world starvation and cannot be a means to world development. Many argue about how this technology could reduce hunger and if genetic engineering is not approved, then people will be dying of starvation in the developing world. She says “I think it’s a ploy. It’s a ploy to convince relatively well-to-do people in the industrialized world to approve of this technology.” She also discusses how poverty is the main cause causing hunger in today’s society. She says “The biggest problem behind hungry people is lack of money. It’s not technology. There’s plenty of food right now, and there’re people starving…Technology is not an obstacle to feeding people. It’s poverty…” In her point of view, the better approach to decreasing hunger would be that people could buy food that will give a well-balanced diet. Instead of having one food containing all the required nutrients, they should be able to buy different diets to fulfill their requirements.
She finds it pointless to apply biotechnology to a variety of problems when there are many simple, practical and feasible alternatives. For example, she discusses how edible vaccines that supposedly are safe, could also cause death. She says ” how are you going to be sure, say, if an edible vaccine is in bananas, that someone doesn’t overdose on vaccines by eating too many bananas?…but I do see people perhaps overlooking more practical but less sensational solutions to very important problems…” She argues how the idea of an edible vaccines is not necessarily beneficial and could have severe outcomes. From her point of view, genetic engineering is strong technology that could change how the world functions and could lead to various successful outcomes. However, she is concerned about the negative outcomes of this technology as is fairly new and has not been monitored for very long. She suggests limited use of genetic engineering. 9 & 1 0
Genetic engineering is one of the most controversial issues which has been and will continue to be raised in media. This process has not only helped to create bug-resistant crops but has also benefitted society economically and socially. This technology is considered one of the healthiest technologies that have recently been discovered. Some scientists agree whereas some disagree with the use of genetic engineering as its use can either be advantageous or disadvantageous, depending on the perspective of the individual. Genetic engineering has proven to be successful at the very moment, however, scientists argue about, if, its negative outcomes are long-term impacts. They are skeptical about whether it would generate troubles that develop over a longer period of time. Moreover, they are concerned about the ecosystem and the functioning of the world as the consequences of genetic engineering are not necessarily safe.
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